Electric switch



Sept. 15, 1925. 1,553,446

B. D. HORTON ELECTRIC SWI TCH Filed April 15, 1919 2 Sheets-Sheet 2 Patented Sept. l5,- 1925.

UNITED STATES PATENT OFFICE.

BBYBON D. HORTON, OI DETROIT, MICHIGAN, ASSIGNOB TO SQUARE D COMPANY, OF DETROIT, MICHIGAN, CORPORATION OF MICHIGAN.

nmcrnrc swrrca.

Application iiled April 15, 1919. Serial H0. 290,314.

To all wlwm it may concern:

,Be it lmown that I, BRYSON D. HORTON, a citizen of the United States, residin at Detroit, in the county of Wayne and tate of Michigan, have invented certain new and useful Improvements in Electric Switches, of which the followin clear-and exact descriptlon thereof.

This invention relates to an interlock for enclosed electrical switches and a disabling device associated with the interlock, and to switch casings in general. Electrical switches have been heretofore enclosed in.

protective casings for the purpose of increasing the safety factor, m order that unskilled workmen may not come in contact with live wires, and also to reduce the fire hazard.

Among the objects of my invention are to provide an externally operated and enclosed switch with an improved form of interlocking device and parts associated therewith which will, first, normally insure that the switch contacts be locked open whenever the cover is open; second, that the cover be locked closed whenever the switch contacts are closed, and, third, that the cover be releasably latched in a completely closed position atall times, thereby preventing'its being accidentally opened when the switch is open. This structure is eminently satisfactory for the protection of the unskilled workman who should not be allowed to come in contact with live parts.

Another object" of my invention is to associate with and incorporate in such a device a means whereby the competent and properly authorized person may temporarily disable the interlocking device and gain access into the interior of the casing for purposes of inspection and test.

As he is able, therefore, to disable the A interlock and obtain access to the interior of the casing, he can make inspection of the switch, contacts, fuses and wiring, etc., without in any way interrupting the flow of current to the load which is being controlled by this box. He will not interfere with whatever work is being done in the factory. Inspection may be made more fre quent and under actual running conditions.

Another object of my invention is to provide a hinge device and easing which can be assembled at a minimum of expense and provide a larger gutter space to accommospecification is a.

date wiring within the interior of the switch enclosure.

Other objects of -my invention will become evident as the description proceeds, and I would have it understood that all objects and advantages are within the scope of my invention, and that I reserve all rights thereto and to the structural equivaput.

In the accompanying drawings, I have shown one complete embodiment of my in vention, but I desire to distinctly state that this showing is for illustrative purposes only, and is not to be considered in a limited sense, as the scope of my invention is to be limited solely by the claims which follow this specification.

In the drawings:

Fig. 1 is a plan view showing my improved structure with the cover completely opened and showing the switch mechanism in the elf position, and the interlock normally functioning.

Fig. 2 is a section on line 2 2 of Fig. 1 taken in the direction of thearrows.

Fig. 3 is a section on the line 3-3 of Fig. 2 taken in the direction of the arrows.

Fig. 4 is a plan view partly broken away showing the switch in the closed position and the cover closed, and also showing in dash and dot the disabling device in the position in which the cover may be opened, even though the switch is closed.

Fig. 5 is a side elevation of the switch shown in Fig. 4; and

Fig. 6 is a side elevation of the switch as shown in Fig. 2, wherein the switch .lents and uses to which the same may be i The houslng for the switch comprises a box like enclosure having a bottom 1, a side 7 wall 2, to which there is hinged a 'cover, an

opposite side wall 3 provided with an open slot 3, and carrying interlocking mechanism and switch operating means, opposite end walls 4 and 5 which may be slotted as shown at 6 for the rece tion of suitable end plates, not shown, for t e connection of conductors, meter adapters and the like. The bottom 1 of the casing may be provided with suitable knock-outs 7 for admittin conductors through the rear or bottom 0% A cover member 8 having a flange 9 provided with a plurality of apertures 10, an opposite flange 11 provided with an open notch 12, and opposite end flanges 13 and 14 is adapted to close the casing and to be opened to afford access to the interior thereof. The hinge device between the cover flange 9 and the casing wall 2 is preferably made by severinga portion 15 of the metal wall 2 and rolling t e same outwardly, passing the free end 16 thereof through aperture 10, and then bringing the free end 16 closely adjacent the outer side of the wall 2. This hinge device is very satisfactory and may be constructed b labor saving machinery. The casing wal 3 also supports a spring catch 17 which is adapted to hold the cover securely closed, this catch being passed through an aperture 18 in the cover. The catch 17 is provided with a projecting prong 19 which will engage with the upper surface of the cover when the cover is completely closed.

.This is brought out clearly in Fig. 5.

An insulating block 20 carrying suitable fixed contacts 21, movable switch blade contacts 22, fuse receptacles 23 and binding post terminals 24 is supported from the bottom 1 of the casing by blocks 25, which will place the insulating base 20 away from the wall of the casing, thereby providing space for carrying wires through the housing, suitable screws 25 being employed as a fastening means. The movable switch contacts 22 are interconnected by suit-able insulating cross bar 26, provided with an upstanding member 27 for operating the crossbar. Pivoted in the walls 2 and 3 of the casing is a switch operating member of U-shaped or bail configuration 28, which is suitably attached to the member 27. The switch operating member 28 is extended through the wall 3 and provided with a suitable operating handle 29 exterior of the casing. By the manipulation of the handle 29, the switch may be opened and closed. An exterior stop 30 is provided to limit the movement of the handle to the open position.

The switch operating member 28 carries, by any suitable fastening means a sector or arcuate shaped member 30 having a stopping shoulder 31 which is adapted to cooperate with a movable hook-shaped locking plate- 32. The wall 3 also carries a housing 33 fastened thereto, this housing supporting the locking plate. This locking plate 32 is pivotally mounted on one of the rivets 33,

the box.

which is used for fastening the housing 38 to the side wall 3. This locking late is provided with a shoulder 34 adapted to cooperate with the stopping shoulder 31 to arrest movement of the switch operating mechanism toward the closed position. A spring 35 biases the [plate 32 against the arcuate member 30 an holds the arts 32 and 34 in engagement, as shown in ig. 6. The housing 33 is open at the top as shown at 34 to permit access to the locking plate 32, this opening being in alinement with the slot 3' in the side wall 3.

The flange 11 on the cover carries a flat flexible spring member 36 riveted thereto, as shown at 36. This resilient member 36 is provided with a pin 37 adapted to roject inwardly through the slot 12, and to held in such position by-a suitable lock 38, cooperating with the hole 39 in the car 40 riveted to the flange 11 on the outer side. The pin 37 is carried by the cover in such position that it will readily enter the opening 34 in the housing 33 and the slot 3, when the cover is moved toward the closed osition. The locking plate 32 is also rovi ed with a portion 41 which is adapte to lie in the path of the pin 37 as the cover is closed, and when the pin 37 engages with the portion 41, it oscillates the plate 32 counter clockwise from the position shown in Fig. 6, to that shown in Fi 5 thereby disengaging the locking shoulder 34 from the stop shoulder 31. At the same time, however, another part 42 of the locking plate 32 has passed above the pin 37, as shown in Fig. 5 so that the pin 37 cannot be raised or the cover opened without oscillating the plate 32 in a clockwise direction. Such oscillation, however, is prevented by the tip of the looking shoulder 34 as it is in engagement with the arcuate member 30. The housing 33 is further secured to the wall 3 by another rivet 43 and the plate 32 is held in place by a spring 44 on the pivot rivet 33.

By the construction so far described, it is impossible to open the cover while the switch is in closed position, and further, it is impossible to close the switch while the cover is in open position. In the position of the cover and locking plate 32 as shown in Fig. 5 and with the switch open with the arcuate plate 30, as shown in Fig. 6, it will be clear that the spring 35 will bias the plate 32 in a clockwise direction, whereby the portion 41 will tend to raise the pin 37, thereby raising the cover to a slight extent. The spring catch 17 and 19, as before described prevents movement of the cover. This operation is of importance for, were the spring 35 to be permitted to move the cover 8, the hook 34 would be moved sufliciently to engage the stop shoulder 31, thereby preventing the closing of the switch uiiless the cover were manually moved. to its full closed position.

The cooperation of tha iinterlock and the spring catch as above described, is of special value when the switch is mounted on a wall, and therefore the weight of the cover has no tendency to retain'the cover closed.

As I have pointed out above, these interlocking devices do not permit inspection of the swltch and associated fuses even by persons who are competent to deal with the apparatus when carrying current. This 'in-- in this view, there is nothing to interfere with opening the cover, as soon as the latch 17 is moved to release the cover from the catch 19. The cover may then be opened irrespective of theposition of the switch operating means, the switch inspected and the cover subsequently closed, the pin 37 returned to its normal position and the lock replaced. All this may be accomplished without in any way interfering with the load which is being normally carried by the switch.

It is, of. course, to be understood that the embodiment above described and illustrated in the drawings could bev changed in many ways without departing from the scope of the following claims; and therefore such matter is intended to be interpreted as illustrative only and not in the-limiting sense.

I claim:

1. A look for the cover of electrical switch casings, comprising a depending flange on the cover, said flange having a notch therein, a resilient member attached to said cover, a pin carried thereby and adapted to pass through said notch, and means within said casing to engage said pin. 1 I

2. In a device of the class described, the combination with an enclosure, a switch, ex ternal operating means for the switch, and interlocking means toprevent access to the switch, comprising a pin on the cover of said enclosure adapted to project into interlocking engagement with a member pivoted on the casing, of means for disabling said interlocking means comprising a resilient mounting for said pin whereby it may be withdrawn from engagement with said member.

3. In a device of the class described, the combination with a casing provided with a hinged cover, a switch, external operating means for the switch, and interlocking .means for preventing access to the switch when closed, comprising a pin mounted on the cover remote from the hinge, of means for disabling. said interlock comprising a resilient mounting for said pin on the cover remote from the hinge whereby the pin may be moved from its interlocking relation.

4. In 'a device of the class described, in combination, an enclosure having a cover, a switch within said enclosure, external opcrating means for said switch, means for preventing access to said switch when the switch is closed, comprising an arcuate member carried by the operating means, a hook shaped. member biased against the arcuate member, connections between the cover and hook shaped member opposing the biasing of the,hook shaped member when the cover is closed, and normally disengageable only when the switch is opened thereby allowing the hook'shapedmember to engage and stop the arcuate member, a lock and means controlled by the removal thereof whereby said connections may be disengaged when the switch is closed.

5. In combination, a switch casing having a cover removable to gain access to the interior thereof, a switch in the casing, operating means for the switch provided with a stop shoulder, a hookpivoted on the casing and arranged to engage the stop shoulder, said hook and wall having coinciding slots, a locking member on the cover adapted to enter said slots as the cover is closed and rock the hook on the pivot to cause the hook to interengage the member on the cover thereby locking the cover closed, and means under the control of a lock whereby the in terengagement of thecover carried membe and the hook may be disabled; A

6. In a device of the class described, the combination with an enclosure, a switch, externaloperating means for the switch, an interlocking means to prevent access to the switch, of means for disabling said interlocking means, comprising a resiliently mounted device, and a removable lock cooperative with said resiliently mounted device to retain' the same in normalv position, the removal of said lock permitting said disabling,

7. In a device of the class described, the combination with a casing provided with a hinged cover, a switch, external operating means for the switch, and interlocking means for preventing access to the switch when closed, said means being remote from the hinge, of means for disabling said interlocking means, comprising an element carried by the cover on the side remote from the hinge, and a removable lock for said element.

8. In an enclosed switch, a switchoperating mechanism, a cover, means for interlocking said cover and said switch operating mechanism, said means comprising a pin, means for carrying said pin comprising a strip resiliently mounted on the flange of the cover remote from the hinge, and means whereby said strip is normally held in such position that the in functions to interlock the cover close 9. In an enclosed switch, a switch operating mechanism, a cover, means for interlocking said cover and said switch operating mechanism, said means comprlsing a pin, a strip extending along the flange of said cover remote from the hinge, the pin being mounted on one end of said strip and the other end thereof being secured to the cover, and locking means for holding the free end of said strip close to the flange to posi tion said pin in operative position, and whereby when said lock is released said free end may be moved and the pin withdrawn to disable said interlock.

10. In an enclosed switch comprising a casing and a cover, fixed and movable contacts, operating means for said switch contacts having a portion thereof exteriorly accessible, and interlocking means whereby said cover cannot be opened while the switch is closed, said last means comprising a member pivotally mounted separately on said casing and a pin mounted on the cover, said pin being resiliently mounted so that it may be moved against the normal bias thereof while the switch is closed to release the interlocking engagement between the cover and casing and thereb permit the cover to be opened although t e switch remains closed.

11. In an enclosed switch comprising a casing and a cover, fixed and movable contacts in said casing, means for operating said switch having a portion thereof exteriorly accessible, interlocking means whereby said cover cannot be opened while said switch contacts are closed, said last means comprising a member pivotally mounted separately on said casing and a pin mounted on said cover, and means whereby said pin may be withdrawn from interlocking engagement with said pivoted member and thus release said interlock to permit the cover to be opened while the switch contacts are in closed position.

12. In an enclosed switch comprising a casing and a cover, fixed and movable contacts, switch operating means comprising an exteriorly accessible portion, interlocking means to prevent the opening of the cover when the switch is closed, said interlocking means comprising a pin mounted on the cover and adapted to be moved transversely and substantially perpendicularly to the other elements of the interlocking means, to release the interlocking engagement and allow the cover to be opened while the switch remains closed.

13. In an enclosed switch, switch operating means having a portion thereof exteriorly accessible, a casing, a cover hinged thereto, said cover having a flange on the side, an interlock between the cover and switch operating means whereby said cover cannot be opened when the switch is in closed position, said interlock com rising a pin mounted on said cover and a a ted to be moved, from the exterior of sai cover, to and from interlocking position in a direction parallel to said cover and substantially perpendicularly to said flange whereby the interlock may be released and said cover opened while the switch remains closed.

14. In an enclosed switch, a casing, a cover hinged thereto, switch operating means in saidcasing having a portion thereof exteriorly accessible, interlocking means whereby said cover cannot normally be opened while said switch is closed, said interlocking means embodying a pin mounted on said cover and projecting through a portion thereof, said pin being adapted to be moved transversely in a direction substantially parallel to said cover and to and from the side wall of said casing to so release said interlock that the cover can be opened While the switch remains closed.

15. In an enclosed switch, a casing, a cover therefor, switch operating means having an exteriorly accessible portion, interlocking means comprising a member separately pivoted on said casing and a pin mounted on said cover and cooperative therewith, said means normally preventing the opening of the cover while the switch is in closed position, and means whereby said pin can be moved to release the interlock and permit the cover to be opened while the switch is closed, said means being such that said pin thereafter returns automatically to normal interlocking position.

16. In an enclosed switch, a switch casing, a movable cover therefor, a switch element in said casing, a handle for operating said switch element, a latch member in said casing, a cooperating catch carried by said handle for locking the switch in open position, a movable bolt for causing said members to be disengaged when the cover is closed, said bolt and latch member also 00- operating to lock the cover closed when the switch element is in closed circuit position, and means for withdrawing said bolt from engagement with said latch member to permit the cover to be opened when the switch is in closed circuit position.

17. In an enclosed switch, a switch casing, a movable cover therefor, a switch element in said casing, a handle for operating said switch element, a latch .member car ried by said casing, a spring pressed bolt carried by said cover and cooperating with said latch member, a member carried by said handle for causing said latch and bolt to interengage and hold the cover closed when the switch element is moved to closed circuit position, and means for withdrawing said bolt from engagement with said latch to permit the cover to be opened when th switch is in closed circuit position.

' 18. In an enclosed switch, a casing, a cover hinged thereto, switch operating means in said casing having a portion thereof exteriorly accessible, interlocking means whereby said cover cannot normally be opened while said cover remains closed, said cover having a flange on the side opposite the hinged sidethereof, and said interlocking means comprising a pin mounted on said flange, said p-in being so mounted that it is movable, by exterior manipulation, to and from the side wall of said casing to release said interlock and allow the opening of said cover while said switch remains closed.

19. In an enclosed switch, a casing, a cover hinged thereto, switch operating means in said casing having a portionthereof exteriorly accessible, interlocking means whereby said cover cannot normally be opened while said cover remains closed, said cover having a flange on the side opposite the hinged side thereof, and said interlocking means comprising a pin mounted on said flange and projecting theretlirough, said pin being so mounted that it may be moved, by exterior manipulation, in a direction away from the side wall of said casing to release it from engagement with the remainder of the interlocking means to disable the latter and allow the cover tobe opened while the switch remains closed.

20. In an enclosed switch, a casing, a cover therefor, switch operatin means in said casing having a portion t ereof exterio-rly accessible, interlocking means whereby said cover cannot normally be opened while the switch is closed, a flange on said cover, a pin-like member so mounted on said flange that it may be moved therethrough from the exterior of the casing, said pin functioning when in its innermost position to lock said cover closed when the switch is closed, and means associated with said pin to permit its being retracted outwardly through said flange to release said interlock and allow the cover to be opened although the switch remains closed.

21. In an enclosed switch, a casing, a cover therefor, switch operating means in said casing having a portion thereof exteriorly accessible, interlocking means whereby said cover cannot normally be opened while the switch is closed, a flange on said cover, and a pin-like member so mounted on said flange that it may be moved therethrough from the exterior of the casing, said pin functioning when in its innermost position to lock said cover closed when the switch is closed, said pin being soconnected with said flange that it may be retracted therethrough from the exterior of the casing to release said interlock and allow the cover to be opened although the switch remains closed.

BRYSON D. HORTON. 

